json_StringIsLargeNumber returns true when the string is not a valid number

[ibrido90]

The function json_StringIsLargeNumber checks only if the string contains '0', 'E', 'e' or '.' characters to say if it's a number or not.
So the string code like this one 012345678901234567890 is recognized as a valid Json number which in reality is not.

We'd like to submit a pull request that patches this issue.

[timhall]

(moved to VBA-JSON)